CBSE 2025 · Region 2 · Set 3 · Q25 · 3 marks

(a)

Using valence bond theory, explain the hybridization and magnetic behaviour of the following : $\displaystyle \mathbf{2}+\mathbf{1}=\mathbf{3}$

(i)

$\displaystyle \left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{6}\right] \mathrm{C} l_{3}$

(ii)

$\displaystyle \mathrm{K}_{2}\left[\mathrm{NiCl}_{4}\right]$ [At. no. : $\displaystyle \mathrm{Co}=27, \mathrm{Ni}=28$ ]

(b)

Write the electronic configuration of $\displaystyle \mathrm{d}^{5}$ ion when $\displaystyle \Delta_{\mathrm{o}}>\mathrm{P}$.

CBSE Class 12 Chemistry past-paper question from the 2025board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.